Electrically operated tool



May 3, 1938. J, WE 2,116,043

ELECTR ICALLY OPERATED TOOL Filed May 16, 1955 I nventm' Attorney Patented May 3, 1 938 UNITED STATES PATENT OFFICE 4 Claims.

My invention relates generally to electrically operated tools, and particularly to a device of this kind which is more compact and is entirely enclosed except for the working bit.

Another important object of my invention is to provide a device of the character indicated in which different forms of bits, such as nail files, nail buffers, and the like may be interchangeably installed for use.

10 Another important object of my invention is to provide a device of the character described in which there are no parts subject to relatively rapid wear, the device being devoid of brushes and having only one principal moving part.

15 Other objects and advantages of my invention will be apparent from a reading of the following description in connection with the drawing, wherein for purposes of illustration I have shown a preferred embodiment of my invention.

20 In the drawing:-

Figure 1 is a general side elevational view of an embodiment of the invention showing the same equipped with a bit, the bit being shown in phantom lines.

25 Figure 2 is alongitudinal vertical sectional View taken, through Figure 1 approximately on the line 2-2.

Figure 3 is a transverse vertical sectional view taken through Figure 1 approximately on the 30 line 3-3.

Referring in detail to the drawing, the numeral 5 generally designates a hollow generally cylindrical elongated casing which would be preferably made of nickel iron or a composition insulat- 5 ing cover shaped to fit the hand and be internally threaded at its open side as indicated by the numeral 6 to receive the reduced threaded part 1 of the cap 8, and the cap 8 is provided with a central axial bore 9.

40 The opposite end of the container has an opening H! in which is located a rubber grommet H which insulates and protects the passage into the interior of the casing of the alternating current conductors I2.

45 Slidable in the bore 9 is the armature shaft 13 which has on its outer end a chuck l4 provided with a clamping set screw l5 or other holding device for connecting the desired working point or tool to the shaft 13.

50 Within the cap 8 the shaft [3 is threaded as indicated by the numeral I 6 to accommodate the spring tensioning nut I! which abuts the small end of the conical spiral spring l8 which is circumposed on the shaft l 3 and has its large inner 55 end engaging the iron washer is which has the opening 20 in which the reduced part of the T- shaped cross section armature 2| works, the reduced portion of the armature having a threaded socket in which the threaded terminal 22 of the armature shaft I3 is threaded.

The washer i9 is concentrically spaced from the interior of the casing 5 and forms a continuation of the core to be described. An iron sleeve 23 concentric with the Washer I9 is disposed and held in position between the inner end of the cap 8 and the right hand side of the washer as shown in Figure 2. A brass sleeve shorter than the sleeve 23 is similarly disposed with respect to the opposite side of the washer I9 and abuts an insulating washer 24. The opposite side of the washer Z4 abuts the right hand end of the wire winding 25 and the opposite end of the winding abuts another insulating washer 26.

u -shaped laminations of magnetically permeable metal which are designated 21 have the inner legs 28 disposed within the hollow winding and the outer legs disposed outside of the winding and along the interior of the casing 5 toward the right as far as and to overlap the washer 24, the brass sleeve, the iron washer, and the iron sleeve 23, as clearly indicated in Figure 2 whereby to hold these parts in their proper relationship.

The inner and outer sides of the winding are properly insulated by such material as impreg 30 nated linen from the inner and outer core legs, the outer core legs being designated 29.

With the alternating current coming into the winding 25 and the spring l8 properly adjusted, the head of the armature 21 which is adjusted to initially closely approach the end of the core adjacent thereto, will be alternately attracted toward and released from the core, so as to reciprocate the armature shaft l3 and give the necessary reciprocating motion to the tool bit which may be connected to the clamping chuck l4.

Although I have shown and described herein a preferred embodiment of my invention, it is to be definitely understood that I do not desire to limit the application of the invention thereto, and any change or changes may be made in the materials, and in the structure and arrangement of the parts, within the spirit of the invention and the scope of the subjoined claims.

What is claimed is: 5

1. An electrical tool comprising a tubular casing, an electro-magnet lying along said casing and having one end spaced from the adjacent end of said casing, a cap closing said adjacent end of the casing and removably threaded therein, said 5 cap being formed with a bore, a longitudinally recip-rocable shaft slidably supported in said bore and having its axially outer end formed with a tool chuck, a magnetizable partition disposed in said casing intermediate saidcap and the adjacent end of said electro-magnet, said magnetizable partition being formed with a bore, an armature comprising a magnetically permeable head located at the magnet side of said partition, said head having a reduced shank slidably engaging the last-mentioned bore, means connecting said reduced shank and the axially inward end of said recip-rocable shaft, a stop on said shaft axially outwardly spaced from said shank, and an expanding spring interposed between said partition and said stop and normally retracting said armature away from said electromagnet.

2. An electrical tool comprising a tubular dielectric casing, an electro-magnet lying along said casing and having one end spaced from one end of said casing, said electro-magnet including a core, a cap closing said one end of the casing and removably threaded therein, said cap being formed with a bore, a longitudinally reciprocable shaft slidably supported in said bore and having its axially outer end formed with a tool chuck, a magnetizable partition disposed in said casing in axially spaced relation to said electro-magnet, said magnetizable partition being formed with a bore, an armature comprising a magnetically permeable head located at the magnet side of said partition, said head having a reduced shank slidably supported in the last-mentioned bore, means separably connecting said reduced shank and the axially inward end of said reciprocable shaft, a stop on said shaft spaced axially outwardly from. said shank, an expanding spring in. terposed between said partition and said stop and normally retracting said armature away from said electro-magnet, said core having a longitudinal extension reaching to and contacting said magnetizable partition.

3. An electrical tool comprising a generally cylindrical elongated outer casing closed at one end and open at its opposite end, a cap removably threaded on and closing said opposite end of the casing, an armature shaft slidably supported by a bore formed in said cap, an electro-magnet within said casing and axially spaced from said cap to define a chamber, a partition in said chamber and spaced from said electro-magnet and from said cap, non-magnetizable means spacing said partition from said electro-magnet, a magnetizable head located in the space between said partition and said electro-magnet, said head having a shank slidably supported in a bore formed in said partition, a sleeve having one end engaged with said partition and its opposite end engaged with a portion of said cap, said partition and said sleeve being thereby held in place by said cap, with said armature shaft extending through said sleeve, means operatively connecting the axially inward end of said armature shaft with said shank, a stopon said shaft adjacent said cap, and a helical spring interposed on said shaft and operatively mounted between said stop and said magnetizable partition.

4. An electrical tool comprising a generally cylindrical elongated outer casing closed at one end and open at its opposite end, a cap removably threaded on and'closing said opposite end of the casing, an armature shaft slidably supported by a bore formed in said cap, an electro-magnet within said casing and axially spaced from said cap to define a chamber, a partition in said chamber and spaced from said electro-magnet and from said cap, non-magnetizable means spacing said partition from said electro-magnet, a magnetizable head, located in the space between said partition and said electro-magnet, said head having a shank slidably supported in a bore formed in said partition, a sleeve having one end engaged with said partition and its opposite end engaged with a portion of said cap, said partition and said sleeve being thereby held in place by said cap, with said armature shaft extending through said sleeve, means operatively connecting the axially inward end of said armature shaft With said shank, a stop on said shaft adjacent said cap, and a helical spring interposed on said shaft and operatively mounted between said stop and said magnetizable partition, said partition and said sleeve being of magnetizable material, and said electro-magnet being provided with an extension contacting both said partition and said sleeve.

JOHN H. ROWE. 

